With respect to an excellent substrate for a high-temperature oxide superconducting compound, an intermediate layer having high crystal orientation (CeO2 or zirconia doped yttrium oxide (YSZ)) is formed on a metal substrate, and a superconducting compound layer (RE123 film: RE: Y, Gd, Ho or the like) is further formed on the intermediate layer.
As a method for forming these oxide films, conventionally, there have been known an ion-assisted-beam film forming method (IBAD method) and a RABITS method where an oxide film is formed on a metal substrate whose crystals are oriented in advance.
To take future production efficiency such as a film forming speed into consideration, a substrate for an oxide superconducting compound manufactured by the RABITS method is advantageous. However, to enhance the superconducting property using such a manufacturing method, it is important to make crystals of the metal substrate highly oriented.
As such a metal substrate, there has been disclosed a substrate where copper is laminated to a stainless steel substrate, crystals of copper are highly oriented, and an intermediate layer made of nickel is laminated to the copper layer (see patent document 1, for example).
Further, as a method for manufacturing such a metal substrate, there has been disclosed a technique where a copper layer which is subjected to high rolling reduction is subjected to heat treatment such that copper crystals in the copper layer are highly oriented, the highly-oriented copper layer is laminated to a stainless steel substrate by cold rolling, and a nickel layer is laminated to the copper layer (see patent document 2, for example).